Current methods for determining the characteristics of sea ice include using active and passive radio-frequency (RF) sensors to correlate measured RF properties with the physical characteristics of the sea ice. The RF characteristics measured may be normalized radar cross section (σ0) and brightness temperature (TB), or reflectivity (r) and emissivity (e). In some ice characterizations both active and passive RF systems are used. However these ice characterizations have been at the algorithm level. In an example, ice concentration data may be retrieved from either single-channel or multi-frequency passive RF systems, and ice concentrations from the same area, but not necessarily acquired simultaneously, may be retrieved from single-frequency active RF systems. The results may be inter-compared for selected areas. Although RMS differences between the active and passive RF algorithms may generally be on the order of 10%, within the range of variability for each sensor algorithm, the lack of time coincidence significantly decreases the agreement for small areas, and increases the error in any one sensor measurement. Some of the disagreement and error may be due to changes in surface conditions between the time of acquiring the RF data and the passive RF data, such as during the summer melt. In addition, because the example synthetic aperture radar (SAR) and passive sensors used for the inter-comparison are single-frequency, inter-comparison of ice type determination may not be possible.